Acicular silicon crystal and process for producing the same

Abstract

By uniformly forming an indefinite number of microscopic acicular crystals on a surface of a silicon substrate so as to be perpendicular to the surface of the substrate by plasma CVD method using a catalyst, it is possible to reliably, homogeneously and massively form an ultramicroscopic acicular silicon crystal having a substantial cone shape tapered so as to have a radius of curvature of not less than 1 nm to no more than 20 nm at its tip end and having a diameter of bottom surface of not less than 10 nm, and a height equivalent to or more than the diameter of bottom surface, at a desired location.

1. A method for producing an acicular silicon crystal which comprises:
 sputtering catalytic metal micro particles by applying a direct-current voltage to a silicon substrate under reduced pressure with the silicon substrate, a target of anode side and a catalyst metal, a target of cathode side opposed to each other in an atmosphere of inert gas to uniformly adhere the catalytic metal micro particles on the silicon substrate; 
 and then generating electron discharge plasma by a microwave power during supplying a hydrocarbon-based gas and a carrier gas on the silicon substrate to form acicular silicon crystals with surfaces coated with a thin carbon film. 
 
     
     
       2. The method for producing an acicular silicon crystal according to  claim 1 , wherein the catalytic metal micro particles comprise Fe. 
     
     
       3. The method for producing an acicular silicon crystal according to  claim 1 , wherein an n-type low resistive silicon substrate having resistivity of 0.1 to 20 Ω·cm is used as the silicon substrate.